The present invention relates to a light control circuit for an illuminated vanity mirror assembly and particularly to a dimming circuit therefor.
Illuminated vanity mirror assemblies are frequently installed in visors for vehicles. U.S. Pat. No. 4,000,404 discloses such a system including in FIG. 15 thereof, a dimming control for providing variable adjustment of the light intensity from the lamps associated with the vanity mirror. The system disclosed is relatively expensive requiring several solid state circuit elements in addition to a variable resistor for providing the dimming control. The utilization of a conventional rheostat, although providing desired dimming, adds considerable bulk and/or expense to a dimming control and can provide a relatively concentrated source of heat which could result in damage to the typically polymeric core utilized in the manufacture of the vanity. Other dimming controls for a vanity mirror installed in a visor are disclosed in U.S. Pat. No. 4,586,788 showing a dimming switch to assure that when the covered vanity mirror is opened, it is always opened in the dim position and U.S. Pat. No. 4,227,242 showing a dimming control as a function of cover movement. The latter two patents provide dimming control primarily to assure that when the cover is opened on the covered vanity mirror assembly, the user is not temporarily blinded by the high intensity of the light.